The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Conventional methods of casing or repairing wells, boreholes, conduits and the like include applying cementation, straddle packers, metallic patches, or through-tubing casing patch using in situ polymerization such as Patch Flex™ (a trademark of Schlumberger) on the wall of the wells, boreholes, or conduits. A Patch Flex system involves an in-situ polymerization technology to install a hard, pressure-resistant seal on the wall along its length. U.S. Pat. No. 6,044,906 (“the '906 patent”) issued to Saltel discloses a conventional Patch Flex system, which comprises an inflatable setting element (“ISE”, called “inflatable tubular sleeve” in the '906 patent) and a preform made of a thermosetting resin and disposed around the ISE. A nozzle which engages the ISE inflates the ISE, which in turn expands the thermosetting preform radially against the wall of the well. When the ISE is completely inflated, the entire thermosetting resin preform is inflated accordingly and is then heated to cause polymerization of the preform. The preform is thus secured to the wall of the well. The ISE is then deflated and removed, leaving in place a permanent hard preform against the wall of well.
The conventional Patch Flex system has a disadvantage in that the casing length or the repair zone of the well is restricted by the length of the ISE because the expansion of the preform depends on fully inflation of the ISE along the length of the ISE. Currently, the ISE can be made to have a length of no more than about 10 meters and thus can repair or case a zone of no more than 10 meters. Moreover, the thermosetting resin preform has a limited lifetime before polymerization and requires more time to heat and cure, thereby prolonging the casing or repair process.